I just can't take Stannis seriously as a character after that.

The dude was so intensely unlikeable and life nitty and we got to see a bit of his soul in his talk with Shireen earlier in the season. The guiding principle to Stannis are duty and his claim to the throne is based on blood/family so yeah, just hand your little daughter over to the evil priestess. Like is this how Stannis wants to be remembered, the would-be king who was enslaved by an insane priestess and sacrificed his daughter to a bloodthirsty god?

It'd be one thing if Stannis were a true believer/fanatic, but the dude is just playing this R'hallor card out of pragmatism. I mean the slugs worked before, it's a big step from some slugs killing off Robb Stark and Joffrey to killing your daughter. anyway...